Aircraft and other vehicles typically use engines, such as turbine-powered engines, jet engines, combustion engines, etc., as a source of power for propulsion systems and for other mechanical and electrical systems. When the aircraft or other vehicles are not in use, the engines may lie dormant. In order to start the engines and prepare them for use, an external rotational force must usually be applied to initiate a reaction that eventually results in continuation rotation of the engine.
Typical engine startup systems may require an additional motor to initiate the external rotational force on the engine during startup. In some systems, a generator that is typically configured to convert mechanical power from the engine into electrical power may be reversed, converting electrical power to mechanical power that is applied to the engine. In this way, the generator may be effectively used as a motor during engine startup. However, in the case of an ISVF generator, merely applying electrical currents to the output of the motor, as a typical aircraft might do, is not sufficient for engine startup because ISVF motors typically have multiple stages of power generation attached to a single rotor. As such, typical engine start systems are not equipped to work with an ISVF generator. Other disadvantages may exist.